Thermostat.



M. BRIGGS.

THERMOSTAT.

v APPLIOATIOH FILED 001222 1908. 992,542. Patented May 16, 1911.

WITNESSES lNVENTOR .To all whom may concern:

Unrran STATES PATENT OFFICE.

MELANCTHOIN J. BRIGGS, or PHILADELPHIA, PENNSYLVANIA.

THERMOSTAT;

Be it known that I, MELANGTHON J.

BRIGGS, a citizen of the United States, re-' siding in the city andcounty of Philadelphia, State of Pennsylvania, have invented a new anduseful Thermostat, of which the following is a specification.

.mnostat, particularly described in the *ficationtherefor, filed June8th, 1908, Serial My invention is concerned with a new form ofelectrical thermostat, such as is employedin a fire alarm circuit toindicate a rise in temp ratureto or beyond certain predetermined egrees.

My invention is designed as an improvement upon my former invention of atherspeci- No. 437,463, and is to be used only in connection witlnandinclosed in, a hermeticallysealed tube or case, which tube or case, willconstitute the expansible member of the thermostat, as described in thesaid specifi cation. g

The object of my invention is to so improve my said former invention, asto have the means of bbth closing and opening the electrical circuits,actuated directly by the expansible member,-.wit-hout the aidof a springoraother device.

My invention is illustrated in the accom-' panying drawings in Which-Figure 1, represents the front elevatlon of g the interior-mechanism ofa thermostat embodying my invention, the casing being shown in sectionand Fig. 2, represents a so inclosed may'liidt'be' corroded, impaired osection'on line 00-40 of Fig. 1;.

The same figures designate the same parts throughout the drawings.

For the purposeof illustrating my inven- -t ion,.'I have shown in saiddrawings, one form thereof, which is-at present preferred by 'me, sincethe same has been found in practice to give satisfactory and reliablere-- Specification of Letters Patent. Patented luay 16, 191 Applicationfiled October 22, 1908.

, side (if should fit so loosely therein as to be readily- Serial No.458,990.

or affected by gases, moisture or dust in the atmosphere surrounding thethermostat, while the expansiblememberis itself so exposed as to beimmediately aifected by any changes in the temperature of suchatmosphere; said expansible member 1, maybe of any metal or substancewhich readily ,expands with-heat and contracts with cold, but preferablyof aincor brass, constructed inany suitable forms, but preferably in theform of a cylindrical tube, or an elongated rectangular afthin but rigidpiece of w0od-,or orcelain,

or some other non-conducting material, but' slightly affected bychiinges of temperature,

extends nearly the entire length of the insaid expansible member 1, .and

moved longitudinally by thecadjusting screw.

' 1-. Said base 2, has a metal block- 6, rigidly atfixed to one endthereof, which block 6 is perforated by a threaded hole 5, fitting theadjusting screw 4, which passes through said hole 5, and holds that endof said base 2 firmly. in position. Adjacent to the otherend of saidbase 2, andrigidly afiixed there to, is a metal plate 10.

' The lever conductor 3, is pivotally attached to said metal plate 19,by its fulcrum pin 12, and the short arm of said lever conductor ispivotally attached to the metal block 9, by the pivot pin 11, the saidblock 9,

and it may be se, with the ends hermetically closed with the samematerial. An adjustable base 2, preferably made of beingv rigidlyattached to the end piece 8,-

of the expansible member 2, and eatendin through the said end piece 8,to the binding post 21. The long arm of said lever ('10 ductor 3,extends down so as to engage the flexible spring contact 19, and topress the same against the contact 2 The adjusting screw 4, passesthrough a closely fitting round hole in the-center ofthe end piece .7,of the expansible member 1, and has a collar 18, so brazed or solderedon to said adjusting screw 4,as to preclude any longitudin al" movementthereof the threaded end. of said adjusting screw 1. passes through thethreaded hole 5, in the block 6, aflixed to the said base 2,. holdingthe end of said adjusting screw 4,106 the right or le thebase 2, ismoved longitudinally, whic forces the long arni -of' said leverconductor 3, toward or away fgrom as said contact 19.

said base 2, firmly in position, By turnirfi The flexible spring contact19, is afiixedgto the base 2, by the metallic pin 13, which ex- Y tendsthrough said base 2, and is attached tothe insulated wire said contactconsists of a flexible spring which will yield to pressure of the longarm of the lever conductor "said base 2, by the metallic pin 14, whichextends through said base 2, and is attached to the insulated wire 16,The contact 20, is so ,placed in reference to the'contact 19, that uit.

when the temperature increases a predetermined number of degrees. abovethat at which the said lever conductor 3, engages said contact 19, saidcontact 19, is forced by the continued pressure of said lever conductor3, againstisaid contact 20, thus closingthe second circuit. The wire 17is attached to thebinding post 21, extending thence to the positive poleof an electric battery.

The' ins'ulated wire 1 5, is attached to the metallic pin 13, andextends through the hermetically sealed hole 22, in'the end 8, of"

the expansible member 1, j and thence, through the armatures of desireds gnals, to the negative pole of said electric battery.

The insulated wire 16, is attached to the mei tallic pin 14, and extendsthrough the saidhermetically sealed hole 22,. and thence, through thearmatures of the distinctive signals of the second circuit, to thenegative pole of said electric battery. Upon the. ex.- terior of the end7, of said expansible memher 1, is placed a dial plate upon which islaid off a scale, so spaced'that the movement of the indicating armattached to the head of the adjusting screw 4, one space on said scale,makes a change of 5 degrees in the temperature required 'to closethefirst circuit.

The-operation of my device will, it is be- 2, being fixed, and the longarm of the lever conductor 3. is thrown to the right and against thel(3(!i1'1(2 ill contact 19, thus closing the first circuit.- Should thetemperature continue to increase, the pressure of the long arm of saidlever conductor 3, will force the flexible spring'19, toward the contact20, and, when it reaches the degree at which contact 20 is set, saidcontact 19, will engage the'contact 20, thus closing the second cirtheshort arm of the lever conductor 3,

A falling temperature will cause a 5 mnesia downward, and the long armthereof to the left,'-and away from the contact 19'; both of secure byLetters Patent is-' 1. In a device of thechara'cter described, thecombination with an expansible member, consisting of an hermeticallyclosed tube or case, an adjustable base inclosed therein, a leverconductor pivotally attached to the said base, one arm of said leverconductor pivotally attached to said expansible memher, an electricalcontact within said expansible member'rigidly affixed to said base inthe path of the other arm of said-lever conductor, and external meansfor adjusting the thermostat by moving said base longitudi nally.

2. Inadevicc of the character described, the combination with ancxpansible member, consisting of an hermetically closed tube, anadjustable base inclosed therein, a

lever conductor having its fulcrum rigidly attached to said base, onearm of said lever conductor pivotally attached to the said ex-..

pansible member, a' flexible spring electrical contact within saidexpansible member attached to said base in the path of the other arm ofsaid lcvcr conductor, a second electrical contact within saidexpansiblcunemher with which the said flexible spring contact willengage at apredeterniincd increase of temperature, whereby a seconddistinct signal may be given, and external means for adjusting thethermostat by moving said base longitudinally.

3. In a device of the character described, the combination with anexpansible men:- bcr, consisting of an hermetically closed tube or case,an adjustable base inclosed therein, a. lever conductor pivoted upon afulcrum rigidly attached tosaid base, a block rigidly -attached to saidexpansible member, one arm of said lever conduct-or 4. In a device ofthe character described,

the con'ibination with an expansible member, conslstmg of anhermetically closed tube or icase, an adjustable base inclosedtherein, a

lever conductor pivoted upon a fulcrum rigidly attached to said base, ablock rigidly attached to said expansible member, one arm of said leverconductor pivotally attached to said block, an electrical contactwithin1 said expansible member independent of said this specification in thepresence of two witlever conductor and attached to said base nesses. inthe path of the other arm of said lever conductor, and'an adjustingscrew anchored I MELANCTHON' BRIGGS 5 in the end piece' of saidexpansible member, Witnesses:

by which said base is moved longitudinally. JNo. LEARY,

In testimony whereof, I hereby subscribe LEON A. CANTER.

